Make IDL Callbacks non-refcounted by default

Source/core/dom/MutationObserver.h

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 52 matching lines @@
     enum ObservationFlags  {
         Subtree = 1 << 3,
         AttributeFilter = 1 << 4
     };
 
     enum DeliveryFlags {
         AttributeOldValue = 1 << 5,
         CharacterDataOldValue = 1 << 6,
     };
 
-    static PassRefPtr<MutationObserver> create(PassRefPtr<MutationCallback>);
+    static PassRefPtr<MutationObserver> create(PassOwnPtr<MutationCallback>);
     static void deliverAllMutations();
 
     ~MutationObserver();
 
     void observe(Node*, const Dictionary&, ExceptionState&);
     Vector<RefPtr<MutationRecord> > takeRecords();
     void disconnect();
     void observationStarted(MutationObserverRegistration*);
     void observationEnded(MutationObserverRegistration*);
     void enqueueMutationRecord(PassRefPtr<MutationRecord>);
     void setHasTransientRegistration();
     bool canDeliver();
 
     HashSet<Node*> getObservedNodes() const;
 
 private:
     struct ObserverLessThan;
 
-    explicit MutationObserver(PassRefPtr<MutationCallback>);
+    explicit MutationObserver(PassOwnPtr<MutationCallback>);
     void deliver();
 
-    RefPtr<MutationCallback> m_callback;
+    OwnPtr<MutationCallback> m_callback;
     Vector<RefPtr<MutationRecord> > m_records;
     HashSet<MutationObserverRegistration*> m_registrations;
     unsigned m_priority;
 };
 
 }
 
 #endif // MutationObserver_h